The present disclosure relates to a multilayer ceramic electronic component and a board having the same.
Multilayer ceramic capacitors (MLCCs), types of multilayer electronic component, are commonly used in electronic apparatuses because of their inherent advantages such as a small size, high capacitance, and ease of mounting.
Meanwhile, with the electrification of vehicles, electronic control of such vehicles has become popular. As a result, the number of electrical control units (ECUs) mounted in such vehicles has increased. Further, operation control systems have increased in complexity due to the need for communications and networking between the ECUs. Finally, each ECU that is directly associated with the safety performance of a vehicle requires strict reliability and durability.
Such ECUs are used in environments in which temperatures are high, sudden changes in temperature can occur, and the ECUs may be exposed to mechanical stresses such as vibrations and shocks for an extended period of time.
Such ECUs may each contain one or more multilayer ceramic capacitors having thermal or electrical reliability characteristics.
The multilayer ceramic capacitors may each include a stack of a plurality of dielectric layers, as well as internal electrodes disposed between the dielectric layers and having different alternating polarities through the stack.
Here, since the dielectric layers each have a piezoelectric property, when a direct current (DC) or alternating current (AC) voltage is applied to the multilayer ceramic capacitor, a piezoelectric phenomenon may occur between the internal electrodes, generating periodic vibrations while expanding and contracting a volume of a ceramic body depending on a frequency of a voltage applied thereto.
The vibrations may be transferred to a board through external electrodes of the multilayer ceramic capacitor and solders connecting the external electrodes and the board to each other, such that the entirety of the board may act as a sound reflecting surface to generate vibration sound, experienced by users as noise.
The vibration sound may correspond to an audio frequency within a range of 20 to 20,000 Hz, causing listener discomfort. The vibration sound causing listener discomfort, as described above, is known as acoustic noise.
There may be a problem in that quality of devices may deteriorate due to acoustic noise.
Meanwhile, as causes of defects in multilayer ceramic capacitors, there may be cracks, or the like, due to the mechanical stress resulting from the vibrations described above. As a result, external moisture may permeate into the multilayer ceramic capacitor, and thus a level of insulating resistance may be reduced and the ECU may fail or otherwise stop operating.
Therefore, a need exists for improving the reliability of multilayer ceramic capacitors used in ECUs.